1. Field of the Invention
The present invention relates to a linear actuator which allows a slider to reciprocate in the axial direction of a main cylinder body by introducing a pressure fluid from fluid inlet/outlet ports.
2. Description of the Related Art
A linear actuator has been hitherto used as a means for transporting a workpiece or the like. Such a linear actuator transports the workpiece placed on a slide table by allowing the slide table to reciprocate linearly along a main cylinder body.
The linear actuator concerning the conventional technique (see, for example, Japanese Utility Model Registration No. 2540597) comprises a main cylinder body which includes a piston movably therein, a rod which is connected to the piston and which protrudes from the side of the main cylinder body to the outside, a table which has a vertically extending section connected to one end of the rod and which is provided displaceably in the axial direction of the main cylinder body, and a linear guide which has a guide block for sliding along a guide rail formed to expand on the upper surface of the main cylinder body.
The linear actuator is operated as follows. When air is supplied to a forward movement port provided on the side of the main cylinder body, then the piston is moved, and the table, which is attached to the upper surface of the main cylinder body, is also moved together. The table is smoothly guided by the linear guide provided between the table and the main cylinder body, and thus the table can reciprocate linearly.
However, in the case of this linear actuator, the following structure is adopted. That is, a stopper is connected to the other end of the rod which is disposed on the side opposite to the table (vertically extending section) and which protrudes from the main cylinder body to the outside. The stopper makes abutment against the end surface of the main cylinder body, and thus the forward movement end of the table is regulated. Therefore, the rod, which has the stopper, protrudes to the outside of the main cylinder body by the stroke length in which the table is moved. Therefore it is not possible to make the entire liner actuator compact in size. Further, this linear actuator does not have with any means for regulating the backward movement end of the table. It is not possible to arbitrarily adjust the stroke amount of the backward movement of the table. Therefore, it is not possible to make the entire apparatus small in size, and ensure the convenience of the apparatus.